Invasiveness Ranking System for Non-Native Plants of Alaska

Competitive Ability (0–3) 0Common mouse-ear chickweed and sticky chickweed cannotcompete with established vegetation (Bonis et al. 1997, Jesson etal. 2000). In an experiment common mouse-ear chickweed hadlow survival of transplants and no germination in undisturbedenvironments due to competition from the surroundingvegetation (Jesson et al. 2000). Growth rate of common mouseearchickweed plants can be decrease by competition with grasses(Bonis et al. 1997).Thicket-forming/Smothering growth form (0–2) 0Common mouse-ear chickweed and sticky chickweed do notform dense patches in Alaska (M. Carslon pers. obs.). Bothspecies do not possess climbing or smothering growth habit(Douglas and MacKinnon 1998, Hultén 1968, Welsh 1974).Germination requirements (0–3) 0Common mouse-ear chickweed requires open soil forgermination and establishment (Jesson et al. 2000). Nogermination and establishment of seedlings were recorded inundisturbed environments in an experiment in New Zealand(Jesson et al. 2000).Other invasive species in the genus (0–3) 0A number of Cerastium species has been introduced into UnitedStates but none of them listed as a noxious weed (USDA, NRCS2006).Aquatic, wetland or riparian species (0–3) 1This species is a weed of roadsides, waste places, gardens andfields (Douglas and MacKinnon 1998, Welsh 1974). It caninvade grasslands, dwarf shrub heath, fern beds, and sanddunes (Broughton and McAdam 2002). However, a survey ofexotic species distributions in Arthur’s Pass National Park, NewZealand found common mouse-ear chickweed to be a speciesprimarily associated with rivers (Jesson et al. 2000). It also isfrequent in grass swards beside rivers in number of islands aroundAntarctica (Walton 1975).Total for Biological Characteristics and Dispersal 8/25Ecological Amplitude and Distribution ScoreHighly domesticated or a weed of agriculture (0–4) 2Common mouse-ear chickweed is a weed of arable andhorticultural lands (Broughton and McAdam 2002, Douglas andMacKinnon 1998).Known level of impact in natural areas (0–6)UCommon mouse-ear chickweed is widespread in grasslands,dwarf shrub heath, fern beds, and sand dunes in the FalklandIslands (Broughton and McAdam 2002). This species colonizesanimal-disturbed areas in Prince Edward Island and in manyislands around Antarctica (Ryan et al. 2003, Walton 1975). InArthur’s Pass National Park, New Zealand, common mouse-earchickweed was found exclusively in riverbeds (Jesson et al. 2000).However, ecological impact of this exotic species on naturalcommunity has not been recorded.Role of anthropogenic and natural disturbance in3establishment (0–5)Common mouse-ear chickweed requires either anthropogenic ornatural disturbance for establishment (Broughton and McAdam2002, Ryan et al. 2002). This species has been recorded on sitescharacterized by intense disturbance by seals and seabirds. Italso occurs on dry slopes or erosion scars (Ryan et al. 2003). Thesurvey of exotic species distribution in Arthur’s Pass NationalPark, New Zealand found common mouse-ear chickweed to bea species primarily associated with sites frequently disturbed byflooding rivers (Jesson et al. 2000).Current global distribution (0–5) 5Cerastium fontanum ssp. vulgare is native to Europe, Asia, andNorthern Africa. It is now found across the world, including arcticand subarctic regions. It has been introduced into North andSouth America, Central and South Africa, India, Australia, andNew Zealand (Hultén 1968, Walton 1975).Extent of the species U.S. range and/or occurrence of5formal state or provincial listing (0–5)Common mouse-ear chickweed is found throughout the UnitedStates and Canada (USDA, NRCS 2006). Cerastium fontanumssp. vulgarum is listed as a noxious weed in Alberta and Manitoba(Rice 2006).Total for Ecological Amplitude and Distribution 15/19Feasibility of ControlScoreSeed banks (0–3) 3Seeds of common mouse-ear chickweed germinated after 8months of dry storage (Williams 1983). In another study mostseeds germinated within 2 years (Brenchley and Warington1930). Seeds may be viable in arable fields for 16 years(Chancellor 1985).Vegetative regeneration (0–3) 1Fragments of stems are likely able to reroot (Ohio perennial andbiennial weed guide 2006).Level of effort required (0–4) 1Small population of common mouse-ear chickweed can becontrolled by hand pulling. Herbicides can be effective whenapplied during active growth (AKEPIC 2005).Total for Feasibility of Control 5/10Total score for 4 sections 34/94§B-19